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Abstract:

Provided is a lens barrel comprising a cylinder that is provided on a base
and that extends in a direction of the axis of the cylinder; a guide axle
that slides in the direction of the axis of the cylinder along an inner
peripheral surface of the cylinder; a first holding component that holds
a first lens and is fixed to the guide axle; and a second holding
component that holds a second lens, which is different from the first
lens, and slides in the direction of the axis of the cylinder along an
outer peripheral surface of the cylinder.

Claims:

1. A lens barrel comprising:a cylinder that is provided on a base and that
extends in a direction of the axis of the cylinder;a guide axle that
slides in the direction of the axis of the cylinder along an inner
peripheral surface of the cylinder;a first holding component that holds a
first lens and is fixed to the guide axle; anda second holding component
that holds a second lens, which is different from the first lens, and
slides in the direction of the axis of the cylinder along an outer
peripheral surface of the cylinder.

2. The lens barrel according to claim 1, further comprising a drive
cylinder that has engaging grooves engaged directly or indirectly with
the first holding component and the second holding component, and that
applies a drive force in the direction of the axis of the cylinder to the
first holding component and the second holding component by rotating
around the axis of the cylinder.

3. The lens barrel according to claim 2, further comprising an
interlocking member that is engaged with the engaging groove of the drive
cylinder, whereinone of the first holding component and the second
holding component indirectly engages with the drive cylinder by engaging
with the interlocking member, androtation of the interlocking member
around the direction of the axis of the cylinder causes a drive force in
the direction of the axis of the cylinder to be applied to the holding
component engaged with the interlocking member.

4. The lens barrel according to claim 2, whereinat least one of the first
holding component and the second holding component has the portion
thereof that is engaged with the engaging groove of the drive cylinder
positioned near the guide axle.

5. The lens barrel according to claim 1, whereinthe first holding
component is fixed to one end of the guide axle.

6. The lens barrel according to claim 1, comprising two of the guide axles
and two of the cylinders corresponding to the two guide axles,
whereinthere is a difference between (i) size of a gap between one of the
guide axles and the cylinder corresponding to the one of the guide axles
and (ii) size of a gap between an other of the guide axles and the
cylinder corresponding to the other of the guide axles.

7. An image capturing apparatus comprising:the lens barrel according to
claim 1; andan image capturing unit that captures an image formed by the
lens barrel.

Description:

BACKGROUND

[0001]1. Technical Field

[0002]The present invention relates to a lens barrel and an image
capturing apparatus. In particular, the present invention relates to a
lens barrel having a plurality of lenses and an image capturing apparatus
provided with the lens barrel.

[0003]The present application claims priority from Japanese Patent
Application No. 2009-45082 filed on Feb. 27, 2009, the contents of which
are incorporated herein by reference.

[0004]2. Related Art

[0005]A conventional lens barrel of a camera is provided with a fixed
cylinder that is fixed to an image capturing unit when mounted on the
image capturing unit, a cam cylinder that rotates relative to the fixed
cylinder, and a plurality of lenses that move in a direction of the
optical axis according to the rotation of the cam cylinder, as disclosed
in Japanese Patent Application Publication No. 2000-89086, for example.

[0006]This lens barrel, however, has various design restrictions that are
necessary for ensuring optical capability. Furthermore, in order to
ensure these optical capabilities while complying with the design
restrictions, the internal configuration of the lens barrel should be as
simple as possible.

SUMMARY

[0007]According to a first aspect related to the innovations herein, one
exemplary a lens barrel may comprise a cylinder that is provided on a
base and that extends in a direction of the axis of the cylinder; a guide
axle that slides in the direction of the axis of the cylinder along an
inner peripheral surface of the cylinder; a first holding component that
holds a first lens and is fixed to the guide axle; and a second holding
component that holds a second lens, which is different from the first
lens, and slides in the direction of the axis of the cylinder along an
outer peripheral surface of the cylinder.

[0008]The summary clause does not necessarily describe all necessary
features of the embodiments of the present invention. The present
invention may also be a sub-combination of the features described above.
The above and other features and advantages of the present invention will
become more apparent from the following description of the embodiments
taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a schematic view of the camera according to the first
embodiment.

[0010]FIG. 2 shows the lens barrel in a wide angle state.

[0011]FIG. 3 shows the lens barrel zoomed to a telephoto state.

[0012]FIG. 4A is a close-up view of the second lens group sliding cylinder
and the surrounding area.

[0013]FIG. 4B is a close-up view of the third and fifth lens group sliding
cylinder, the fourth lens group sliding cylinder, and the surrounding
area.

[0014]FIG. 5A is a cross-section along the line A-A of FIG. 4B.

[0015]FIG. 5B is a cross-section along the line B-B of FIG. 4B.

[0016]FIG. 6A is a diagram for describing the movement of each lens group
during zooming.

[0017]FIG. 6B is a diagram for describing the movement of each lens group
during zooming.

[0018]FIG. 7A is a diagram for describing the movement of each lens group
during focusing.

[0019]FIG. 7B is a diagram for describing the movement of each lens group
during focusing.

[0020]FIG. 8 is a cross-sectional view of the lens barrel according to a
second embodiment in a wide angle state.

[0021]FIG. 9 is a cross-sectional view of the lens barrel according to the
second embodiment in a telephoto state.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0022]Hereinafter, some embodiments of the present invention will be
described. The embodiments do not limit the invention according to the
claims, and all the combinations of the features described in the
embodiments are not necessarily essential to means provided by aspects of
the invention.

[0023]The following describes a camera according to a first embodiment of
the present invention and a lens barrel used by this camera, with
reference to FIGS. 1 to 7.

[0024]FIG. 1 is a schematic view of the camera 500 according to the first
embodiment. The camera 500 includes an image capturing unit 200 and a
lens barrel 100.

[0025]The image capturing unit 200 includes a case 210, an optical system,
a focal point detection apparatus 230, a shutter 234, an image capturing
element 238, a main LCD 240, and a main control section 250. The optical
system includes a main mirror 212, a pentaprism 214, and an ocular
optical system 216 housed in the case 210.

[0026]When in the state shown in FIG. 1, the main mirror 212 guides the
majority of incident light from the lens barrel 100 to a focusing screen
222 arranged thereabove. The focusing screen 222 is arranged at a focal
position of the optical system in the lens barrel 100, and focuses the
image formed by the optical system in the lens barrel 100.

[0027]A pentaprism 214 guides the image formed by the focusing screen 222
to the ocular optical system 216 via the half mirror 224, after the image
is reflected. In this way, the image on the focusing screen 222 can be
viewed as a normal image through the ocular optical system 216. In this
case, the half mirror 224 superimposes a display image indicating image
capturing conditions, setting conditions, and the like formed by the
finder LCD 226 onto the image of the focusing screen 222. Accordingly,
the image seen at the output end of the ocular optical system 216 is a
combination of the image of the focusing screen 222 and the image of the
finder LCD 226. A portion of the light output from the pentaprism 214 is
guided to the photometric unit 228, and the photometric unit 228 measures
the intensity of the incident light, the distribution of this intensity,
or the like.

[0028]The focal point detection apparatus 230 detects a focal adjustment
state, i.e. a focus state, of the optical system in the lens barrel 100
based on the light that is passed through the main mirror 212 and
reflected by the secondary mirror 232 provided on the back of the main
mirror 212. During image capturing, the main mirror 212 and the secondary
mirror 232 are raised to the position shown by the dotted line in FIG. 1
to be removed from the optical path of the incident light from the lens
barrel 100.

[0029]The shutter 234 is arranged behind the main mirror 212, where
"behind" refers to a position further along the optical path of the
incident light from the lens barrel 100. During image capturing, the
shutter 234 opens in conjunction with the raising of the main mirror 212
and the secondary mirror 232. When the shutter 234 is in the open state,
the incident light from the lens barrel 100 is incident to the image
capturing element 238 via the optical filter 236. The image capturing
element 238 converts the image formed by the incident light into an
electric signal.

[0030]The main LCD 240 has a display screen portion that is exposed to the
outside of the case 210. This display screen portion of the main LCD 240
displays, in addition to the image formed on the image capturing element
238, i.e. the captured image, various types of setting information or the
like concerning the image capturing unit 200.

[0031]The main control section 250 controls the operation of the various
components described above. The main control section 250 also performs
auto-focus, which involves referencing the information concerning the
focal adjustment state of the optical system detected by the focal point
detection apparatus 230 in the image capturing unit 200 to drive the
first through fifth lens groups L1 to L5 of the optical system in the
lens barrel 100, and focus-aid, which involves referencing the movement
amount of the optical system in the lens barrel 100 and displaying
information concerning the focus on the finder LCD 226.

[0032]The following is a detailed description of the configuration of the
lens barrel 100 referencing FIGS. 2 to 5B.

[0033]FIGS. 2 and 3 show cross-sectional views of the lens barrel 100.
FIG. 2 shows the lens barrel 100 in a wide angle state and FIG. 3 shows
the lens barrel 100 zoomed to a telephoto state. As shown in FIGS. 2 and
3, the lens barrel 100 includes first through fifth lens groups L1, L2,
L3, L4, and L5 arranged on a common optical axis AX. In the following
description, the position of the first lens group L1 is referred to as
being at the "front" or "forward" side of the optical axis AX, and the
position of the fifth lens group L5 is referred to as being at the "rear"
or "back" side of the optical axis AX.

[0034]As shown in FIGS. 1 and 2, the lens barrel 100 includes a fixed
cylinder 10, a first lens group sliding cylinder 11 that holds the first
lens group L1, a second lens group sliding cylinder 12 that holds the
second lens group L2, a third and fifth lens group sliding cylinder 13
that holds third and fifth lens groups L3 and L5, and a fourth lens group
sliding cylinder 14 that holds the fourth lens group L4.

[0035]The fixed cylinder 10 is fixed to the image capturing unit 200 by
the base 10a. In this fixed state, the end surface 10b on the image
capturing unit 200 side of the fixed cylinder 10 closely contacts the
image capturing unit 200, i.e. the case 210 in FIG. 1, such that the
fixed cylinder 10 is fixed to the image capturing unit 200, thereby
determining the position of the lens barrel 100 relative to the image
capturing unit 200. The fixed cylinder 10 supports a guide pipe 36A near
a top of the internal peripheral surface thereof, i.e. a ceiling portion,
and supports a guide pipe 36B near a bottom of the internal peripheral
surface thereof.

[0036]The first lens group sliding cylinder 11 is movably connected to a
zoom drive cylinder 16 arranged on an inner side of the first lens group
sliding cylinder 11. More specifically, a cam pin 15 provided on the
first lens group sliding cylinder 11 is engaged with a can groove 16a
formed on the zoom drive cylinder 16.

[0037]The zoom drive cylinder 16 is movably connected to a zoom operation
ring 18 that rotates around the optical axis AX along the outermost
periphery of the lens barrel 100. More specifically, a drive force
transmitting pin 19 protruding outward from the zoom drive cylinder 16 is
engaged with a operation groove 18a that is formed on the inner surface
of the zoom operation ring 18 and parallel to the optical axis AX. As a
result, the zoom drive cylinder 16 rotates in response to the rotation of
the zoom operation ring 18. The zoom operation ring 18 has a rubber layer
to stop slippage formed on the outer peripheral surface thereof, so that
that zoom operation ring 18 does not move to the front or rear. During
the scaling operation, i.e. zooming, the zoom operation ring 18 is
rotated by a user.

[0038]The zoom drive cylinder 16 can rotate relative to a zoom guide
cylinder 22 provided on an inner side thereof. As shown in the bottom
half of FIGS. 2 and 3, the zoom guide cylinder 22 has a recessed groove
22a passing therethrough, and a rotation connecting member 21 fixed to
the cam ring 20 provided on the inner side of the fixed cylinder 10 is
engaged with the zoom guide cylinder 22 and the linear groove 16b passing
through the zoom drive cylinder 16. The cam ring 20 has a cam groove 20e
that engages with a cam pin 10d protruding from an inner side of the
fixed cylinder 10.

[0039]With the above configuration, when the zoom operation ring 18 is
rotated, the zoom drive cylinder 16 rotates in response to the action of
the drive force transmitting pin 19 and, as a result of this rotation and
the cam pin 15, the first lens group sliding cylinder 11 moves backward
and forward, i.e. in a direction along the optical axis AX. Furthermore,
when the zoom drive cylinder 16 rotates due to the rotation of the zoom
operation ring 18, this rotational force is transmitted to the earn ring
20 via the rotation connecting member 21, and therefore the cam ring 20
moves backward and forward while rotating. The zoom guide cylinder 22
moves backward and forward together with the zoom drive cylinder 16
without rotating.

[0040]A cover cylinder 17 is provided between the zoom operation ring 18
and the first lens group sliding cylinder 11. As shown in FIGS. 2 and 3,
the cover cylinder 17 moves backward and forward together with the first
lens group sliding cylinder 11 and seals the space between the zoom
operation ring 18 and the first lens group sliding cylinder 11, thereby
preventing dust from entering into the lens barrel 100.

[0041]FIG. 4A is a close-up view of the second lens group sliding cylinder
12 and the surrounding area. As shown in FIG. 4A, the second lens group
sliding cylinder 12 includes a holding cylinder 24 that holds the second
lens group L2, a pressing ring 26 fixed to the holding cylinder 24, and
an engaging cylinder 28 that is provided to surround the outer periphery
of the holding cylinder 24. The holding cylinder 24 and the pressing ring
26 are fixed by a screw clamp or the like, and grip the outer border of
the second lens group L2.

[0042]The engaging cylinder 28 supports two guide bars 30A and 30B. The
guide bars 30A and 30B are arranged symmetrically at top and bottom
positions across the optical axis AX. As shown in FIGS. 2 and 3, the
guide bar 30A is slidably inserted into the guide pipe 36A supported by
the fixed cylinder 10, and the guide bar 30B is slidably inserted into
the guide pipe 36B supported by the fixed cylinder 10. There need not be
complete contact between the guide bars 30A and 30B and the guide pipes
36A and 36B, and contact is only necessary at regions near the ends of
the guide pipes 36A and 36B.

[0043]The material of the guide bars 30A and 30B is a strong and
light-weight material, such as steel, and the space between (i) the guide
bars 30A and 30B and (ii) the engaging cylinder 28 is fixed using a
process such as adhesion or pressurizing. The material of the guide pipes
36A and 3613 may be the same as that of the guide bars 30A and 30B, e.g.
steel. Here, the guide pipes 36A and 36B have diameters of approximately
2 to 3 mm and thicknesses (the difference between the internal and
external diameters) of approximately 0.3 to 0.4 mm. In the present
example, the internal diameter of the guide pipe 36A and the external
diameter of the guide bar 30A are practically the same. The inner
diameter of the guide pipe 36B is somewhat greater than that of the guide
pipe 36A to provide a small space between the guide pipe 36B and the
guide bar 30B. By ensuring a space between the guide pipe 36B and the
guide bar 30B, it is possible to allow for a manufacturing error (gutter)
in the space between the guide bars 30A and 30B.

[0044]Returning to FIG. 4A, a protruding follower 28a is formed on a
portion of the outer peripheral surface of the engaging cylinder 28. The
follower 28a engages with the circumferential groove 32c of the
interlocking ring 32 provided on the outer side of the engaging cylinder
28. The follower 28a is arranged near the guide bar 30A, specifically,
near an axis extending from the guide bar 30A.

[0045]An interlocking groove 32a and a cam follower 32b are further formed
on the interlocking ring 32 on which the circumferential groove 32c is
formed. One end of an interlocking key 34, which is substantially
L-shaped, engages with the interlocking groove 32a. The interlocking key
34 is connected to the focus ring 37 provided on the outer periphery of
the fixed cylinder 10, as shown in FIGS. 2 and 3, and moves rotationally
around the optical axis AX according to the rotation of the focus ring 37
around the optical axis AX. When the interlocking key 34 moves
rotationally around the optical axis AX in this way, the interlocking
ring 32 rotates around the optical axis AX. Furthermore, the interlocking
key 34 is connected to the motor 38 provided in the motor chamber 10c of
the fixed cylinder 10. Accordingly, the interlocking ring 32 also rotates
around the optical axis AX according to the rotational movement of the
interlocking key 34 around the optical axis AX caused by the rotational
performance of the motor 38.

[0046]As shown in FIGS. 2 and 3, the earn follower 32b engages with the
cam groove 20b formed on the cam ring 20. Accordingly, when the
interlocking ring 32 rotates, the interlocking ring 32 and the components
connected to the interlocking ring 32 (the second lens group sliding
cylinder 12, the guide bars 30A and 30B, and the second lens group L2)
move backward and forward due to the cam groove 20b and the cam follower
32b. In this backward and forward movement, the interlocking ring 32
moves backward and forward while rotating around the optical axis AX, but
the movement of the guide bars 30A and 30B is restricted to only backward
and forward movement by the guide pipes 36A and 36B, and so the second
lens group sliding cylinder 12 and the second lens group L2 connected to
the guide bars 30A and 30B move backward and forward without rotating.
The cam follower 32b is arranged near the guide bar 30A, specifically,
near an extended axis of the guide bar 30A.

[0047]FIG. 48 is a close-up view of the third and fifth lens group sliding
cylinder 13, the fourth lens group sliding cylinder 14, and the
surrounding area. As shown in FIG. 4B the third and fifth lens group
sliding cylinder 13 holds the third lens group L3 and the fifth lens
group L5 on the optical axis AX with a prescribed interval therebetween.
The third and fifth lens group sliding cylinder 13 includes two engaging
members 13a and 13b that engage with the guide pipe 36A and one engaging
member 13e that engages with the guide pipe 368.

[0048]The engaging member 13b (and 13a) has a circular through-hole 31, as
shown in FIG. 5A, which is a cross-section along the line A-A of FIG. 4B.
The through-hole 31 has about the same diameter as the guide pipe 36A,
and when the guide pipe 36A is inserted through the through-hole 31, the
weight of the third and fifth lens group sliding cylinder 13 is supported
by the guide pipe 36A. Here, "about the same diameter" means that the
dimensions of the through-hole 31 are such that a gap sufficient to
prevent interference with sliding of the third and fifth lens group
sliding cylinder 13 is created between the guide pipe 36A and the
through-hole 31. The engaging member 13c has a U-shaped groove 33. The
width of the U-shaped groove 33 is substantially equal to the diameter of
the guide pipe 36B, specifically, the dimensions of the U-shaped groove
33 are such that a gap sufficient to prevent interference with sliding of
the third and fifth lens group sliding cylinder 13 is created. By
engaging the guide pipe 36B with the U-shaped groove 33, the rotational
movement of the third and fifth lens group sliding cylinder 13 around the
guide pipe 36A is prevented. Instead of the U-shaped groove 33, the
engaging member 13c may have an elongated hole with a length in the
upward and downward direction.

[0049]As shown in FIG. 5A, a cam follower 35 is formed to protrude from a
portion of the outer periphery of the third and fifth lens group sliding
cylinder 13. The cam follower 35 engages with the cam groove 20c formed
on the cam ring 20. Therefore, when the cam ring 20 rotates around the
optical axis AX, this rotation causes the third and fifth lens group
sliding cylinder 13 to receive a drive force in the direction of the
optical axis AX. The third and fifth lens group sliding cylinder 13 is
engaged with the guide pipes 36A and 36B as described above, and so moves
in the backward and forward direction without rotating around the optical
axis AX. In FIGS. 4B, 2, and the like, the cam follower 35 and the cam
groove 20c are not shown for the sake of convenience.

[0050]As shown in FIGS. 4B and 5A, an upper aperture 13d is formed on an
upper portion of the third and fifth lens group sliding cylinder 13, and
a lower aperture 13e is formed on a lower portion of the third and fifth
lens group sliding cylinder 13.

[0051]As shown in FIG. 4B, the fourth lens group sliding cylinder 14 is
provided in the internal space of the third and fifth lens group sliding
cylinder 13. An upper portion of the fourth lens group sliding cylinder
14 is revealed through the upper aperture 13d of the third and fifth lens
group sliding cylinder 13, and a lower portion of the fourth lens group
sliding cylinder 14 is revealed through the lower aperture 13e of the
third and fifth lens group sliding cylinder 13. As shown in FIG. 4B,
engaging members 14a and 14b engaging with the guide pipe 36A are formed
on the upper portion of the fourth lens group sliding cylinder 14, and an
engaging member 14c engaging with the guide pipe 36B is formed on the
lower portion of the fourth lens group sliding cylinder 14.

[0052]The engaging member 14a (and 14b) has a circular through-hole 41, as
shown in FIG. 5B, which is a cross-section along the line B-B of FIG. 4B.
The through-hole 41 has about the same diameter as the guide pipe 36A,
i.e. the diameter of the through-hole 41 is such that a gap sufficient to
prevent interference with sliding of the fourth lens group sliding
cylinder 14 is created, and when the guide pipe 36A is inserted through
the through-hole 41, the weight of the fourth lens group sliding cylinder
14 is supported by the guide pipe 36A. The engaging member 14c has a
U-shaped groove 43. The width of the U-shaped groove 43 is substantially
equal to the diameter of the guide pipe 36B, specifically, the dimensions
of the U-shaped groove 43 are such that a gap sufficient to prevent
interference with sliding of the fourth lens group sliding cylinder 14 is
created. By engaging the guide pipe 36B with the U-shaped groove 43, the
rotational movement of the fourth lens group sliding cylinder 14 around
the guide pipe 36A is prevented. Instead of the U-shaped groove 43, the
engaging member 14c may have an elongated hole with a length in the
upward and downward direction.

[0053]As shown in FIG. 5B, a cam follower 45 is formed to protrude from a
portion of the outer periphery of the fourth lens group sliding cylinder
14. The cam follower 45 engages with the cam groove 20d (see FIG. 5A)
formed on the cam ring 20. Therefore, when the cam ring 20 rotates around
the optical axis AX, this rotation causes the fourth lens group sliding
cylinder 14 to move in the direction of the optical axis AX. In this
case, since the fourth lens group sliding cylinder 14 is engaged with the
guide pipes 36A and 36B as described above, the fourth lens group sliding
cylinder 14 moves in the backward and forward direction without rotating
around the optical axis AX. In FIGS. 4B, 2, and the like, the cam
follower 45 and the cam groove 20d are not shown for the sake of
convenience.

[0054]As shown in FIG. 5A, the cam followers 35 and 45 are arranged near
the guide pipe 36A. Here, "near the guide pipe 36A" refers to a region
within 45 degrees of the guide pipe 36A. By arranging the cam followers
35 and 45 near the guide pipe 36A in this way, the force from the cam
followers 35 and 45, i.e. the drive force in the backward and forward
direction, is applied near the guide pipe 36A, and so the each sliding
cylinder 13 and 14 is moved efficiently via the cam followers 35 and 45.
If there were no design restrictions, the cam followers 35 and 45 would
desirably be as close to the guide pipe 36A as possible.

[0055]The following describes the movement of the second through fifth
lens groups L2 to L5 when the zoom operation is performed and when the
focusing operation is performed, with reference to FIGS. 6 and 7. In
FIGS. 6 and 7, to simplify the diagrams, the portion displaying the
operation of the first lens group L1 is omitted.

[0056]First, the movement of each lens group during zooming is described
with reference to FIGS. 6A and 6B. This example describes the zooming the
lens barrel 100 from a wide angle state (FIG. 6A) to a telephoto state
(FIG. 6B).

[0057]From the state shown in FIG. 6A, when the zoom operation ring 18
(see FIG. 2) is rotated by a user, the cam ring 20 rotates via the
rotation connecting member 21 and the like as described above. This
rotation causes a rotational force and a backward and forward movement
force to be applied to the interlocking ring 32 via the cam follower 32b,
but the interlocking ring 32 is guided only in the backward and forward
direction by the interlocking key 34 engaged with the interlocking groove
32a in a fixed state, and so the interlocking ring 32 moves forward
without rotating. Furthermore, the forward movement of the interlocking
ring 32 causes the engaging cylinder 28 engaged with the interlocking
ring 32, the second lens group sliding cylinder 12, and the second lens
group L2 to also move forward.

[0058]The rotation of the cam ring 20 also causes the third and fifth lens
group sliding cylinder 13 and the fourth lens group sliding cylinder 14,
which are engaged thereto via the cam followers 35 and 45, to move
forward, thereby moving the lens groups L3 to L5 forward. The distances
that the third and fifth lens groups L3 and L5 and the fourth lens group
L4 move differ according to the formation direction (angle) of the cam
grooves 20c and 20d engaged with the cam follower 35 and the cam follower
45. Since the cam ring 20 itself also moves forward, the actual distance
moved by each of the third through fifth lens groups L3 to L5 is the sum
of the distance moved by the cam ring 20 and the distance moved by the
cam followers 35 and 45 due to the cam grooves 20c and 20d.

[0059]When zooming in this way, the rotation of the zoom operation ring 18
causes each of the second to fifth lens groups L2 to L5, and the first
lens group L1 that is not included in the current description, to move
forward individually by a certain distance (except for third and fifth
lens groups L3 and L5, which both move the same distance).

[0060]The following describes the movement of each lens group when
focusing, with reference to FIGS. 7A and 7B. Focusing is assumed to begin
from the state shown in 7A, and proper focus is assumed to be reached at
the state shown in FIG. 7B.

[0061]First, when the interlocking key 34 moves rotationally around the
optical axis AX due to rotation of the focus ring 37 by the user or
rotational drive from the motor 38, the interlocking ring 32 engaged with
the interlocking key 34 rotates around the optical axis AX as described
above. Due to this rotation, the interlocking ring 32 moves forward as
the cam follower 32b follows the cam groove 20b of the cam ring 20. The
forward and rotational movement of the interlocking ring 32 causes the
engaging cylinder 28, which has the follower 28a engaged with the
circumferential groove 32c of the interlocking ring 32, the second lens
group sliding cylinder 12, and the second lens group L2 to move forward.
Here, the cam follower 32b and the follower 28a are arranged near the
guide bar 30A, and so the drive force in the direction of the optical
axis AX is efficiently applied to the interlocking ring 32 and the
engaging cylinder 28.

[0062]The cam ring 20 is in a fixed non-rotating state, and therefore the
third and fifth lens groups L3 to L5 do not move forward or backward.
Furthermore, the first lens group L1, which is not included in the
present description, also does not move forward or backward.

[0063]When focusing in this way, the rotation of the interlocking key 34
causes only the second lens group L2 to move forward or backward. In this
case, the third and fifth lens group sliding cylinder 13 and the fourth
lens group sliding cylinder 14 are not directly contacting the guide bars
30A and 30B fixed to the second lens group sliding cylinder 12, and
therefore the forward or backward motion of the second lens group sliding
cylinder 12 is not impeded by the third and fifth lens group sliding
cylinder 13 or the fourth lens group sliding cylinder 14.

[0064]The rotation of the motor 38 during focusing is controlled by the
main control section 250 shown in FIG. 1 based on the detection result of
the focal point detection apparatus 230. In other words, auto-focusing is
performed by the main control section 250 controlling the rotation of the
motor 38. Connection terminals provided between the lens barrel 100 and
the image capturing unit 200 are used to provide an electrical connection
therebetween, and therefore the image capturing unit 200 can supply power
to the lens barrel 100, e.g. to the motor 38 or the like.

[0065]As described above, according to the first embodiment of the present
invention, the guide bars 30A and 30B provided on the second lens group
sliding cylinder 12 holding the second lens group L2 slide along the
inner peripheral surface of the guide pipes 36A and 36B provided on the
fixed cylinder 10 and extending in the direction of the optical axis AX,
and the third and fifth lens group sliding cylinder 13 holding the lens
groups L3 and L5 and the fourth lens group sliding cylinder 14 holding
the fourth lens group L4 slide in the direction of the optical axis AX
along the outer peripheral surface of the guide pipes 36A and 3613. As a
result, the lens sliding cylinders 12, 13, and 14 can move along the same
components. Therefore, the configuration inside the lens barrel 100 can
be simplified. Furthermore, the third and fifth lens group sliding
cylinder 13 and the fourth lens group sliding cylinder 14 do not contact
the guide bars 30A and 30B provided on the second lens group sliding
cylinder 12, and therefore, even when the second lens group sliding
cylinder 12 moves independently during focusing or the like, the other
sliding cylinders 13 and 14 do not obstruct the sliding of the guide bar
30A. Therefore, the force necessary for moving the second lens group
sliding cylinder 12 can be decreased, and the burden placed on the motor
38 or on the user when rotating the focus ring 37 can be decreased.

[0066]Furthermore, according to the present embodiment, the cam follower
32b of the interlocking ring 32 engages with the cam groove 20b of the
cam ring 20 and the follower 28a of the second lens group sliding
cylinder 12 engages with the circumferential groove 32c of the
interlocking ring 32, and so the cam ring 20 and the interlocking ring 32
are indirectly connected to each other. Therefore, when the cam ring 20
rotates while the position of the interlocking ring 32 in the rotational
direction is fixed, the cam groove 20b and the cam follower 32b cause the
interlocking ring 32 to rotate around the optical axis AX together with
the second lens group sliding cylinder 12. Furthermore, when the
interlocking ring 32 rotates while the position of the cam ring 20 in the
rotational direction is fixed, the cam groove 20b and the cam follower
32b cause the interlocking ring 32 itself to move in the forward and
backward direction, which causes the second lens group sliding cylinder
12 to also move in the forward and backward direction. In this way, in
the embodiment of the present invention, the second lens group sliding
cylinder 12 can be moved in the forward and backward direction by either
the rotation of the cam ring 20 or the rotation of the interlocking ring
32.

[0067]Furthermore, in the present embodiment, the cam followers 35 and 45
formed on the sliding cylinders 13 and 14 are provided near the guide
pipe 36A, and therefore the movement (drive) of the sliding cylinders 13
and 14 is achieved efficiently.

[0068]The first embodiment described a case in which the interlocking ring
32 is a ring, but this component may have a different shape, such as part
of a ring having only the portions that achieve the function of the
interlocking ring 32 and from which all other portions are removed.

[0069]In the first embodiment described above, the cam follower 32b and
the follower 28a are provided near the guide bar 30A and the cam
followers 35 and 45 are provided near the guide pipe 36A, but instead, at
least one of these components may be arranged near the guide bar 30A or
the guide pipe 36A.

[0070]The following describes a second embodiment of the present invention
with reference to FIGS. 8 and 9. FIGS. 8 and 9 show a cross-sectional
view of the lens barrel 100' according to the second embodiment. FIG. 8
shows the lens barrel 100' in a wide angle state and FIG. 9 shows the
lens barrel 100' zoomed to a telephoto state. The configuration of the
second embodiment differs from the configuration of the lens barrel 100
in that the second lens group does move in the direction of the optical
axis AX during focusing. The following description includes only points
that differ from the first embodiment.

[0071]In the lens barrel 100' of the second embodiment, the engaging
cylinder 28 forming the second lens group sliding cylinder 12 has a cam
follower 28a, and the cam follower 28a directly engages with the cam
groove 20b of the cam ring 20.

[0072]With this configuration as well, when the user rotates the zoom
operation ring 18 to perform zooming, this rotation causes the cam ring
20 to rotate around the optical axis AX in the same manner as in the
first embodiment. Due to this rotation, the second lens group sliding
cylinder 12, i.e. the second lens group L2, the third and fifth lens
group sliding cylinder 13, and the fourth lens group sliding cylinder 14,
i.e. the third to fifth lens groups L3 to L5, can move in the forward and
backward direction.

[0073]The second embodiment is created in consideration of a case where
the second lens group is a specialized zooming lens. Accordingly, the
focusing is performed by a lens other than the second lens group. A
configuration that performs the focusing by moving the first lens group
L1 is known as a front lens focusing type.

[0074]In the second embodiment, in the same manner as described above in
the first embodiment, the guide bars 30A and 30B provided on the second
lens group sliding cylinder 12 holding the second lens group L2 slide
along the inner peripheral surface of the guide pipes 36A and 36B
provided on the fixed cylinder 10 and extending in the direction of the
optical axis AX, and the third and fifth lens group sliding cylinder 13
holding the third and fifth lens groups L3 and L5 and the fourth lens
group sliding cylinder 14 holding the fourth lens group L4 slide in the
direction of the optical axis AX along the outer peripheral surface of
the guide pipes 36A and 3613. As a result, the lens sliding cylinders 12,
13, and 14 can move along the same components. Therefore, the
configuration inside the lens barrel 100 can be simplified.

[0075]In each of the above embodiments, when focusing, some or all of the
first to fifth lens groups L1 to L5 may move. A configuration in which
all of the lens groups move is known as a total-focusing type.

[0076]In each of the above embodiments, the manufacturing error (gutter)
of the interval between the guide bars 30A and 3013 is compensated for by
having the inner diameter of the guide pip 3613 be larger than that of
the guide pipe 36A, but instead, the manufacturing error (gutter) of the
interval between the guide bars 30A and 30B may be compensated for by
forming the outer diameter of the guide bar 3013 to be smaller than that
of the guide bar 30A.

[0077]In each of the above embodiments, the guide pipes 36A and 3613 are
formed separately from the fixed cylinder 10 and are supported by the
fixed cylinder 10, but the configuration is not limited to this. For
example, the guide pipes 36A and 36B may be formed integrally with the
fixed cylinder 10.

[0078]In each of the above embodiments, the third and fifth lens groups L3
and L5 are supported by a single lens sliding cylinder 13, but instead,
the third and fifth lens groups L3 and L5 may each be held by individual
lens sliding cylinders, for example.

[0079]The number of lens groups and arrangement of the lens groups in the
above embodiments are merely examples. Any lens barrel having at least a
lens held by one lens sliding cylinder fixed to a guide bar and a lens
held by another lens sliding cylinder that slides along the outer
peripheral surface of a guide pipe is acceptable.

[0080]In each of the above embodiments, parts provided with male
components such as the cam followers and the followers may instead be
provided with female components such as the cam grooves and the
circumferential grooves, and parts provided with female components such
as the cam grooves and the circumferential grooves may instead be
provided with male components such as the cam followers and the
followers.

[0081]In the manner described above, the configuration of a lens barrel
and an image capturing apparatus can be simplified. While the embodiments
of the present invention have been described, the technical scope of the
invention is not limited to the above described embodiments. It is
apparent to persons skilled in the art that various alterations and
improvements can be added to the above-described embodiments. It is also
apparent from the scope of the claims that the embodiments added with
such alterations or improvements can be included in the technical scope
of the invention.

[0082]The operations, procedures, steps, and stages of each process
performed by an apparatus, system, program, and method shown in the
claims, embodiments, or diagrams can be performed in any order as long as
the order is not indicated by "prior to," "before," or the like and as
long as the output from a previous process is not used in a later
process. Even if the process flow is described using phrases such as
"first" or "next" in the claims, embodiments, or diagrams, it does not
necessarily mean that the process must be performed in this order.